Pressure-proof reproducer



Jan. 13, 1948. W.'A. MYERS PRESSURE-PROOF REPRODUCER 2 Sheets-Sheet l 7Filed July 1, 1944 INVENTOR. WILLIAM A. MYERS ATTORNEY Jan. 13, 1948, w.A. MY RS 2,434,469-

' PRESSURE-PROOF REPRODUCE-R 2 Sheets-Sheet 2 Filed July 1, 1944INVENTOR. WILLIAM A. MYERS ATTORNEY Patented Jan. 13, 1948 PRESSUREmnoor REPRODUCER William A. Myers, San Diego, Calif., assignor to theUnited States of America, as represented by the Secretary of the NavyApplication July 1, 1944, Serial No. 543,149

4 Claims. (01. 181--31) This invention relates to reproducers and moreparticularly to those of a type in which the speaker may be submerged ina liquid medium under high pressure.

Where speakers are used in and around water, it is often necessary forthem to remain partially or wholly covered with water for considerableperiods of time, and yet to be ready for immediate use. Unless means areutilized for protecting the speaker cone (and associated circuits), theunits soon become inoperable. For example, where such speakers are usedon piers, ships or submarines, they may be thoroughly wettedperiodically, and additionally, may be subjected to great pressures dueto water depth or explosions, if mounted externally of a submarine as apart of an inter-communicating system.

The present invention provides means for protecting a speaker from theeffects of submergence and pressure without unduly altering itsoperating characteristics. This is generally accomplished by housing thespeaker in a waterand pressure-proof housing and providing a flexible,water-proof diaphragm over a portion or all of the face of the speaker.

In the drawings:

Fig. 1 is a sectional view of one form of the invention with portions oithe unit shown in elevation.

Fig. 2 is a sectional view along the line 2-2 of Fig. 1.

Fig. 3 is a sectional View of another form of the invention. 1iFig. 4 isa sectional view along the line 4-4 of The form of the inventionillustrated in Figs. 1 and 2 comprises a relatively heavy, metal,cylindrical housing I which is capable of withstand ing considerablepressure. A mounting plate 2 is welded at 2 to one of the ends of saidhousing to form a waterand pressure-proof closure. This plate isprovided with several mounting holes as at 3. At the opposite end of thehousing is an outwardly extending flange 4 provided with a series ofthreaded holes, as at 5, for a purpose to be described. The outer end ofthe wall of the housing I is also provided with a groove, as at B, toreceive a circular rubber or neoprene gasket 1.

The open end of the housing is closed by meansof a heavy, circular,metal baffle 8, provided with an upstanding circumferential flange 9.This flange is drilled with a series of holes positioned for alignmentwith the threaded holes in the flange 4 so that the baffle may betightly secured,

against the housing I and gasket 1 by means of bolts Ill. The baffle isprovided with a plurality of chamfered-edged holes, as at II, extendingover its surface.

A conventional cone type speaker I2 (such as a J enson ST-443 permanentmagnet unit) is positioned within the housing I and is secured to thebaffie 8 by means of bolts I3 and washers I4.

A flexible, water-proof diaphragm I5, which may conveniently be ofrubber or neoprene, is

placed over the outer face of the bafiie and is secured in place betweenmetal ring I6 (also drilled to receive bolts l0) and flange 9 on battle8. Externally of the flexible diaphragm I5 is positioned a wire grilleor screen I! to protect the diaphragm from mechanical injury. Thisgrille is held in place by another ring I8, similar to ring l6, and isalso drilled to receive the bolts I0. Thus, when the bolts aretightened, the various elements are brought tightly together and thespace within the housing I is made water-tight by means of gasket 1 anddiaphragm I5. A conventional water-tight stufling box I9 is provided onthe housing through which leads (not shown) may be brought forconnection to the speaker I2.

Another and similar form of the invention is illustrated in Figs. 3 and4. This unit is designed to withstand greater pressures without loss ofsensitivity or output than the unit illustrated in Figs. 1 and 2.

The housing I, mounting plate 2, speaker I2, and the stuffing box I9 maybe identical to those on the unit shown in Figs. 1 and 2. In this unitthe flange 4 on the open end of the housing is made somewhat thicker sothat the bolts Ill do not extend completely through it. On the open endof the housing is a flat, metal bafiie 8, similar to the one illustratedin Figs. 1 and 2. However, instead of a, plurality of holes, it isprovided with a single, centrally positioned, hole, as at 20. Thespeaker I2 is similarly mounted against the bafile 8, by means of boltsI3 and washers I4.

In this form of the invention, a cone-shaped plug 2| is glued in thelower end of the speaker cone. This plug should preferably be light inweight and securely bonded to the cone; it has been found that one ofLucite serves very well. In this form of the invention, a short cylinder22 of approximately to 1" in length supports a flat, stiff, circulardiaphragm 23. This diaphragm is of slightly less diameter than the innerdiameter of ring I6 as shown in Fig. 4, and is provided with a series ofmounting cars 24 positioned to be engaged by bolts II]. This diaingmedium. A Micarta diaphragm, .01" thick;

has proven very satisfactory for this purpose.

The rod 25 is surrounded by a small circular sheet of rubber 21 which issecured to the baffle 8 around its circumference :by'ia metal "ring 28'and bolts 29 in order to prevent passage of water through theperforation in the baffle. The center of the rubber sheet is secured bymeans of a washer 30, fixed to the rod 25, and a small collar 3|surrounding the rod?and extending between the :washer 30 andthediaphragm :23. This joint may :be: tightened and made water proof bytightening the nut 26--on the outer end of the rod, which seals therubber sheet between the.

collar and the washer. n theopposite sideof the washer is positionedasmall rubber pressure seal 32 arranged and adapted to engage the baiileand seal the perforation, as :at 20. s

The assembly is completed by the provisioniof ring wand-a grille +1, andmayinclude a ring 16 as used in connection with the form shown :in Figs.v1 'and2. I 1

It is seen that the rod 25 transmitsianyzmotion of the speakercone tothe diaphragm 23, whereby it effectively operates as the :speaker cone.Since water may enter the space between the hostile and. the diaphragm,there .is no pressure differential on opposite sides of the diaphragmin'order'that damage due .to high pressures is prevented. Onthe otherhand, the washer .30, seal Sland rod 25 serve. asfa mechanical stop sothat the pressure .difierenc'e (with reference to the space within the:housing) .is borne by" the washer and the sealb restingfagainst the:baiila. Even under maximum pressures, the diaphragm isrdisplaced for adistance equal only to the-distancehetween :bafiie. and pressure sealwhich may be made of the order-of 1 The rubber sheet and the sealprevent water from contacting :thespeakercone and, if the perforation inthexbafe fie is made small, even pressures corresponding to igreatdepths or vproduceizlby explosions .aresn ot likely to damage thesensitive elements of the speaker IZ. i

It has been found that if the device just de scribed is mounted on theopen bridge of a submarine, the passage of sound through the bafllepermits it to be operated either as a speaker era microphone when thesubmarine is on the surface. When the submarine is submerged, noattention need be given to the speaker, as the water-tight constructionof the unit prevents water from reaching the sensitive parts of thespeaker, and the structure prevents damage by great pressures. Uponcoming to the surface, the unit is ready for immediate operation.

Having described my invention, I claim:

1. A loudspeaker adapted to be submerged in alliquid under pressurecomprising: a relatively heavy tubular housing, closed at one of itsends; a cone-type "speaker positioned in said housing,

tracing the'opemend-of said housing; a relativelyv fheavypperforatedbafiie secured to the open end of r-said :hou'sing; 1a relatively stiffdiaphragm, mounted externally of said perforated baffle; 'm'eansextendingthrough a perforation in said bafiie connecting the cone ofsaid speaker to said diaphragm; and flexible means connected to saidbafiie and said last mentioned means arranged and adapted to prevent theflow of said liquid therebetween.

2. In the device described in claim 1, a stop fixed to said means,extending through a perforation positioned .to engage said baffle forlimiting the movement of said means extending through a perforation.

3. .A loudspeaker adapted to be submerged in a liquid. under pressurecomprising: a relatively .heavy, tubular housing, closed at one of itsends; a cone-type speaker positionedninsaid housing, facing the open endOf said housing; arelatively heavy baffie havinga central perforation,secured to the open .end of saidhousing; a relatively stifi' diaphragm,mounted rexternally of .said housing; rigid means extending through theperforation in said bafile connecting thecone of said speaker and saiddiaphragm; and means comprising a flexible, water-proof sheet securedbetween said. bafile .and said rigid means.

4. In the device described in .claim 3, astop fixed to said. rigid meanspositioned to engage said baffle for limiting, the .movement of .saidrigid means.

WILLIAM A....MYER'S.

EREEEEENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,346,226 Marlow Apr. 11, 1944FOREIGN PATENTS Number Country Date I I 425,186 Great Britain Mar.8,1935

